The present invention relates to switching mechanisms of vehicle seats. More particularly, the present invention relates to switching mechanisms of vehicle seats that are capable of switching slide lock devices between locked conditions and unlocked conditions.
Conventionally, a vehicle seat (a front vehicle seat) having a walk-in function is already known. The vehicle seat is arranged and constructed to make a space between the seat and a rear seat when a passenger gets in and out the rear seat. In particular, such a vehicle seat is arranged and constructed such that a seat back of the seat is rotated forwardly from a predetermined rotational position or use (vertical) position to a rotated or tilted position while a seat cushion of the seat (the entire seat) is slid forwardly. According to this construction, it is possible to easily make space between the seat and the rear seat. Therefore, the passenger can easily get in and out the rear seat via the space.
Such a vehicle seat is taught, for example, by Japanese Laid-Open Patent Publication Number 2004-58928, which corresponds to U.S. Pat. No. 6,986,551. The seat has a fold-down function of a seat back of the seat in addition to the walk-in function. Therefore, the seat back can be rotated forwardly from a use (vertical) position to a folded position.
The seat has a slide lock device that can be changed or switched between a locked condition in which the seat cushion is allowed to slide relative to a floor and an unlocked condition in which the seat cushion is not allowed to slide relative to the floor. The slide lock device is associated with a switching mechanism that is capable of switching the slide lock device between the locked condition and the unlocked condition.
The slide lock device is constructed to be switched to the unlocked condition via the switching mechanism when the walk-in function is used (i.e., when the passenger gets in and out the rear seat). Further, the slide lock device is constructed to be switched to the unlocked condition and then be immediately returned to the locked condition (before the seat back reaches the folded position) via the switching mechanism when the fold-down function is used.
In particular, the switching mechanism includes a link mechanism that is linked to the slide lock device. The link mechanism is arranged and constructed to switch the slide lock device to the unlocked condition when the seat back is rotated forwardly from the use position toward the folded position over a desired angle (when the seat back is rotated to a desired tilted position). That is, when the seat back is rotated to the desired tilted position, the link mechanism is operated or moved by a force caused by rotational motion of the seat back, so as to switch the slide lock device to the unlocked condition.
Further, when the seat back is maintained in the desired tilted position, the link mechanism of the switching mechanism is maintained in an operable condition. As a result, the slide lock device is maintained in the unlocked condition. However, when the seat back can be rotated toward the folded position beyond the desired tilted position, the link mechanism of the switching mechanism is changed to an inoperable condition. As a result, the slide lock device is switched to the locked condition again.
Further, when the seat back is raised or rotated backwardly from the folded position toward the use position, the link mechanism of the switching mechanism can be maintained in the inoperable condition. As a result, the slide lock device is maintained in the locked condition.